Sexually Transmitted Diseases

Essentials of Diagnosis

• All sexually transmitted diseases (STDs) have subclinical or latent periods, and patients may be asymptomatic

• Simultaneous infection with several organisms is common

• All patients who seek STD testing should be screened for syphilis and HIV

• Partner notification and treatment are important to prevent further transmission and reinfection in the index case

General Considerations

• The most common sexually transmitted diseases (STDs) are

  • Gonorrhea

  • Syphilis

  • Condyloma acuminatum

  • Chlamydial genital infections

  • Herpesvirus genital infections

  • Trichomonas vaginitis

  • Chancroid

  • Granuloma inguinale

  • Scabies

  • Louse infestation

• Shigellosis, hepatitis A, B, and C, amebiasis, giardiasis, cryptosporidiosis, salmonellosis, and campylobacteriosis may also be transmitted by sexual (oral–anal) contact, especially in men who have sex with men

• Bacterial vaginosis may be sexually transmitted among women who have sex with women

• Homosexual contact and increasing, bidirectional heterosexual transmission are the typical methods of transmission of HIV

• Ebola virus and Zika virus have both been associated with sexual transmission

Sexual assault

• Victims of assault have a high baseline rate of infection

  • Neisseria gonorrhoeae, 6%

  • Chlamydia trachomatis, 10%

  • Trichomonas vaginalis, 15%

  • Bacterial vaginosis, 34%

• The risk of acquiring infection as a result of the assault is significant but is often lower than the preexisting rate

  • N gonorrhoeae, 6–12%

  • C trachomatis, 4–17%

  • T vaginalis, 12%

  • Syphilis, 0.5–3%

  • Bacterial vaginosis, 19%

• The likelihood of HIV transmission from vaginal or anal receptive intercourse when the source is known to be HIV positive is 1–5 per 1000, respectively

Symptoms and Signs

• See individual diseases

Laboratory Tests

• Simultaneous infection by several different agents is common

• Laboratory examinations are of particular importance in the diagnosis of asymptomatic patients during the subclinical or latent phases of STDs

• All patients who seek STD testing should also undergo routine testing for HIV

Sexual assault

• Victims should be evaluated within 24 h after the assault and cultures or nucleic acid amplification tests for N gonorrhoeae and C trachomatis should be performed

• Vaginal secretions are obtained for Trichomonas wet mount and culture, or point-of-care testing

• If a discharge is present, if there is itching, or if secretions are malodorous, a wet mount should be examined for Candida and bacterial vaginosis

• A blood sample should be obtained for immediate serologic testing for syphilis, hepatitis B, and HIV

Medications

Prophylactic therapy

• The usefulness of prophylactic therapy for victims of sexual assault is controversial

• Prophylactic therapy may include postexposure hepatitis B vaccination without hepatitis B immune globulin; postexposure prophylaxis (PEP) of HIV; treatment for chlamydial, gonorrheal, or trichomonal infection; and emergency contraception

• Testing should be repeated only if the victim has symptoms

• If the status of the source is not known, and the victim presents within 72 hours of the assault, no firm recommendations can be made and the decision to treat is case-by-case

• If the patient seeks care > 72 hours after the assault, prophylaxis is not recommended

Therapeutic Procedures

• As a rule, sexual partners should be treated simultaneously to avoid prompt reinfection

• Prompt treatment of contacts is facilitated by giving antibiotics to the index case to distribute to contacts and has been shown to prevent further transmission

Follow-Up

• Follow-up examination for STD after an assault should be repeated within 1–2 weeks, since concentrations of infecting organisms may not have been sufficient to produce a positive test result at the time of initial examination

• If prophylactic treatment was given, tests should be repeated only if the victim has symptoms

• If prophylaxis was not administered, the victim should be seen in 1 week so that any positive tests can be treated

• Follow-up serologic testing for syphilis and HIV infection should be performed in 6, 12, and 24 weeks if the initial tests are negative

Prevention

• Early initiation of antiretroviral therapy in HIV-infected individuals can prevent HIV acquisition in an uninfected sex partner

• Preexposure prophylaxis with a once-daily pill containing tenofovir plus emtricitabine has been shown to be effective in preventing HIV infection among high-risk men who have sex with men, heterosexual women and men, transgender women, and persons who inject drugs

When to Refer

• Patients with a new diagnosis of HIV

• Patients with persistent, refractory or recurrent STDs, particularly when drug resistance is suspected